Gaming machine and method of controlling the same

ABSTRACT

A random number selector selects at least one random number. A display displays at least one of plural symbols in accordance with the selected random number, the plural symbols including at least one first symbol which is associated with a second symbol in a one-to-one correspondence. A replacement controller replaces the first symbol with the second symbol when a predetermined requirement is satisfied under a condition that the first symbol is displayed in the display.

BACKGROUND OF THE INVENTION

[0001] The invention relates to a gaming machine which displaystemporary symbols and changes the thus-displayed temporary symbols intosubstantial symbols associated therewith when a predeterminedrequirement is satisfied, as well as a method of controlling the gamingmachine.

[0002] For example, U.S. Pat. No. 5,152,529 describes a gaming machineequipped with inner reels and outer reels. In this gaming machine, when“BLANK” is stationarily displayed on the outer reel, the inner reel isfurther spun, to thereby stationarily display a specific symbol throughthe blank. Specifically, the gaming machine performs two independentlottery operations; that is, lottery operation for the outer reel andlottery operation for the inner reel.

[0003] However, the technique for displaying symbols using the outer andinner reels has become well known to players. Therefore, a new techniquefor displaying symbols which arouses the players' interests is desired.Particularly, many types of gaming machines using video reels haverecently been known. Since the video reels can effect a variety ofdisplay operations, a suitable technique for the video reels to displaysymbols has been expected.

SUMMARY OF THE INVENTION

[0004] It is therefore an object of the invention to provide a gamingmachine which can enhance a player's expectation and arouse the player'sinterest, as well as a method of controlling such a gaming machine.

[0005] In order to achieve the above object, according to the invention,there is provided a gaming machine, comprising:

[0006] a random number selector, which selects at least one randomnumber;

[0007] a display, which displays at least one of plural symbols inaccordance with the selected random number, the plural symbols includingat least one first symbol which is associated with a second symbol in aone-to-one correspondence; and

[0008] a replacement controller, which selects the first symbol with thesecond symbol when a predetermined requirement is satisfied under acondition that the first symbol is displayed in the display.

[0009] In such a configuration, the player cannot determine the natureof the second symbol by only the appearance of the first symbol.Accordingly, when the first symbol has been displayed, the player willhave a large expectation for the nature of the second symbol which willappear in association with the first symbol. Moreover, emergence of asecond symbol serves as a chance for the player gaining a profit. Forexample, emergence of the second symbol may be used as a requirement foractivating a bonus game or for offering a large amount of payment. As aresult, when the first symbol has appeared, the player's interest can bearoused in relation to whether or not the first symbol transforms to thesecond symbol or in relation to the nature of the second symbol whichwill appear in association with appearance of the first symbol.

[0010] Preferably, the plural symbols includes plural kinds of firstsymbols appearances of which are different from each other.

[0011] In such a configuration, even when the first symbol is displayed,the player encounters difficulty in predicting the nature of the secondsymbol. As a result, when the first symbol has appeared, the player'sexpectation can be enhanced.

[0012] Preferably, the display first displays the plural symbolsvariably, and then displays at least one of the plural symbolsstationarily in accordance with the selected random number.

[0013] In such a configuration, the invention can be applied to a gamingmachine equipped with physical reels and video reels.

[0014] Here, it is preferable that the predetermined requirement is thata plurality of first symbols are stationarily displayed in the display.

[0015] In such a configuration, when one of the first symbol is firstdisplayed, the player's expectation can be enhanced.

[0016] It is also preferable that the plural symbols includes at leastone third symbol, and the predetermined requirement is that the firstsymbol and the third symbol are stationarily displayed in the display.

[0017] In such a configuration, when the first symbol is displayed, theplayer's expectation for display of the third symbol can be enhanced.When the first symbol and the third symbol have been displayed, thefirst symbol transforms to the second symbol, the player's expectationfor appearance of the second symbol can be enhanced.

[0018] Here, it is preferable that the predetermined requirement is thatthe first symbol and a plurality of third symbols are stationarilydisplayed in the display.

[0019] In such a configuration, when the first symbol is displayed, theplayer's expectation for display of the plurality of third symbols canbe enhanced. When the first symbol and the plurality of third symbolshave been displayed, the first symbol transforms to the second symbol,and the player's expectation for appearance of a second symbol can beenhanced.

[0020] It is also preferable that the predetermined requirement is thata predetermined time period elapses from when the first symbol isstationarily displayed in the display.

[0021] In such a configuration, when the first symbol is displayed, theplayer's expectation can be enhanced.

[0022] It is also preferable that the gaming machine further comprises acluster in which the plural symbols are arranged according to apredetermined order with regard to the first symbol. The displaycomprises a plurality of display areas, each operable to display theplural symbols arranged in the cluster.

[0023] In such a configuration, since the clusters are identical witheach other in terms of a layout pattern in connection with the firstsymbol, the player encounters difficulty in predicting appearance of asecond symbol associated with the first symbol on the basis of thesymbols appearing in the vicinity of the first symbol.

[0024] It is alternatively preferable that the gaming machine furthercomprises a plurality of clusters in which the plural symbols arearranged according to different orders with regard to the first symbol.The display comprises a plurality of display areas, each operable todisplay the plural symbols arranged in one of the clusters.

[0025] In such a configuration, when a certain first symbol has beenstationarily displayed, since the pattern into which symbols are to bearranged around the first symbol differs from one cluster to anothercluster, the player becomes able to predict a second symbol associatedwith the first symbol by the symbols located in the vicinity of thefirst symbol. As a result, a predictive function (declaring occurrenceof a win) can be realized, thereby arousing the player's interest.

[0026] According to the invention, there is also provided a method ofcontrolling a gaming machine, comprising steps of:

[0027] selecting at least one random number;

[0028] displaying, in a display, at least one of plural symbols inaccordance with the selected random number, the plural symbols includingat least one first symbol which is associated with a second symbol in aone-to-one correspondence; and

[0029] converting the first symbol into the second symbol when apredetermined requirement is satisfied under a condition that the firstsymbol is displayed in the display.

[0030] Preferably, the plural symbols are variably displayed first, andthen at least one of the plural symbols is displayed stationarily inaccordance with the selected random number.

[0031] Here, it is preferable that the predetermined requirement is thata plurality of first symbols are stationarily displayed in the display.

[0032] It is also preferable that the plural symbols includes at leastone third symbol, and the predetermined requirement is that the firstsymbol and the third symbol are stationarily displayed in the display.

[0033] Here, it is preferable that the predetermined requirement is thatthe first symbol and a plurality of third symbols are stationarilydisplayed in the display.

[0034] It is also preferable that the predetermined requirement is thata predetermined time period elapses from when the first symbol isstationarily displayed in the display.

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above objects and advantages of the present invention willbecome more apparent by describing in detail preferred exemplaryembodiments thereof with reference to the accompanying drawings,wherein:

[0036]FIG. 1 is a perspective view showing the appearance of a gamingmachine according to an embodiment of the invention;

[0037]FIG. 2 is a block diagram showing the electrical configuration ofthe gaming machine;

[0038]FIGS. 3 and 4 are flowcharts showing operation performed in thegaming machine; and

[0039]FIGS. 5 through 8 are views showing example displays in a symboldisplay of the gaming machine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] A gaming machine according to an embodiment of the invention willbe described hereinbelow. On the basis of a result of internal lotteryoperation (random number selection), the gaming machine of theembodiment displays a plurality of types of symbols including temporarysymbols associated with substantial symbols in a one-to-onecorrespondence. Here, the substantial symbols have specific designs andcharacteristics capable of offering a specific payment to a player whenappearing on a pay line. On the other hand, the temporary symbols havethe function of masking the substantial symbols. The temporary symbolsare associated with the substantial symbols in a one-to-onecorrespondence in advance. When a predetermined requirement has beensatisfied, the temporary symbol transforms to the substantial symbol. Atthis time, the nature of the substantial symbol appears for the firsttime. The predetermined requirement of the embodiment is that a triggersymbol must appear simultaneously with display of the temporary symbol.Specifically, the trigger symbol has the function of transforming thetemporary symbol to the substantial symbol.

[0041] As shown in FIG. 5, a symbol 62, which shows a submarine pier andappears in a block of a fifth reel 75, is taken as a temporary symbol inthe embodiment. Further, as shown in FIG. 5, a symbol 60, which shows asubmarine 61 and appears in a block of a first reel 71, is taken as atrigger symbol. As shown in FIG. 7, a symbol 70, which shows a treasurechest and appears in a block of the fifth reel 75, is taken as asubstantial symbol. Moreover, as shown in FIG. 8, a symbol 80, whichshows ruins and appears in the block of the fifth reel 75, is taken as asubstantial symbol. The substantial symbol 70 is given the function ofactivating a “treasure chest game” when appeared on a pay line. Thesubstantial symbol 80 is given the function of activating a “ruins game”when appeared on the pay line. These substantial symbols are usuallydisplayed as the temporary symbol 62 shown in FIG. 5 so that the playerdoes not know the nature of the symbol.

[0042] When the temporary symbol 62 is displayed along with the triggersymbol 60, the thus-displayed temporary symbol 62 is transformed into asubstantial symbol associated therewith. Here, a plurality of types ofsymbols, including the temporary symbol 62, may be variably displayed.On the basis of a result of internal lottery (random number selection),the variably-displayed symbol may be stationarily displayed, therebyenabling application of the invention to a gaming machine having aphysical reel and a video reel. As a result, the player's expectationfor a symbol to be stationarily displayed can be enhanced. Further, theplayer's interest can be aroused in relation to whether or not anappearing temporary symbol is transformed to a substantial symbol and inrelation to the nature of a substantial symbol which will appear.

[0043] The invention can be applied to all gaming machines capable ofdisplaying symbols. The invention will now be described by taking, as anexample, a gaming machine which can variably display a plurality oftypes of symbols in the direction of a column (or in the direction of arow) and stationarily display the variably-displayed symbol on the basisof a result of internal lottery operation (random number selection).Mechanical drums (reels) may be used for a section of the machine wheresymbols are to be variably displayed. Alternatively, video reels whichvariably display symbols as images on a liquid-crystal screen or thelike may also be employed. The invention can also be applied to askilled-stop type gaming machine which enables the player to determinetimings at which the drums (reels) are to be stopped and a sequence inwhich the drums are to be stopped by actuation of stop buttons at theplayer's will, as in the case of a slot machine. The invention can alsobe applied to a gaming machine in which reels automatically,sequentially come to a halt regardless of the player's will, as in thecase of a slot machine. The embodiment will be described by takingtokens as gaming values. However, the invention is not limited to thetokens; all mediums capable of offering gaming values may be adopted.

[0044] As shown in FIG. 1, a gaming machine 1 is constituted of ahousing 2, and a front panel 3 reclosably attached to the front of thehousing 2. Attached to the back of the front panel 3 is a symbol display7 which is formed from a liquid-crystal panel or cathode ray tube (CRT)and displays symbols in, e.g., five lines. The embodiment adopts a videoreel system, and five reels are displayed on the symbol display 7 byexecution of a program.

[0045] As shown in FIG. 5, the symbol display 7 has five reels whichvariably and stationarily display symbols in the direction of a column(i.e., the vertical direction of the gaming machine). Specifically, thesymbol display 7 has a first reel 71, a second reel 72, a third reel 73,a fourth reel 74, and a fifth reel 75. Each reel can variably orstationarily display various symbols.

[0046] The symbol display 7 includes a plurality of temporary symbols ofidentical appearance. Specifically, the temporary symbols each have thesame submarine pier. The temporary symbols are associated with differentsubstantial symbols in a one-to-one correspondence. In the symboldisplay 7, there are formed a plurality of clusters which are identicalwith each other in terms of a layout pattern into which symbols are tobe arranged, with each temporary symbol being taken as a center. Here,the cluster is a group formed from a plurality of symbols. As mentionedabove, the plurality of types of symbols are variably displayed in thedirection of a column. On the basis of a result of internal lottery, thevariably-displayed symbols are stationarily displayed. Since theclusters are identical with each other in terms of a layout pattern intowhich, when a certain temporary symbol has been displayed, the playerencounters difficulty in predicting appearance of a substantial symbolassociated with the temporary symbol on the basis of the symbolsappearing in the vicinity of the temporary symbol.

[0047] For example, there is provided the case of a reel which variablydisplays symbols in the direction of a column (i.e., the verticaldirection of the gaming machine) and three symbols; one in an upper row,one in a middle row, and the other in a lower row. In this case, therespective clusters assume the same layout pattern; that is, two symbolsappearing at a position above a temporary symbol, and two other symbolsappearing at a position below the temporary symbol. More specifically,under the assumption that symbols are represented as capital letters,the layout pattern of symbols in each cluster is defined as, e.g., “B,C, A, D, E” from the upper side to lower side of the reel. As a result,when temporary symbols are displayed in the upper row, “A, D, E” appearin each cluster. When temporary symbols are displayed in the middle row,“C, A, D” appear in each cluster. When temporary symbols are displayedin the lower row, “B, C, A” appear in each cluster. In this way,symbols, including the temporary symbols, are arranged in the samepattern as are those belonging to the cluster. Since the layout patternsare identical for all the cluster, difficulty is posed on the player inpredicting a substantial symbol to which a displayed temporary symbol istransformed, thereby enhancing the player's expectation.

[0048] A token insertion slot 10 and a token return button 10 a to beused for returning tokens when inserted coins have caused clogging areprovided on the front of the housing 2. A start lever 11 is a lever forstarting rotational display (variable display) of the symbol display 7.

[0049] The gaming machine 1 starts a game by the player specifying avalid pay line (i.e., a payout line). There player can set a pluralityof pay lines, e.g., a horizontal center line, horizontal upper and lowerlines, and sloped lines. BET operation is performed by insertion of atoken into the token insertion slot 10 to be described later or bybetting some of the tokens reserved by a reserved token insert button21. The BET operation can also be performed by combined use of these BEToperations.

[0050] When the pay line has been specified through the player's BEToperation and the player has actuated the start lever 11, the symboldisplay 7 variably displays symbols. When a predetermined period of timehas lapsed, the symbol display 7 sequentially stops thevariably-displayed symbols. The symbols are stopped in sequence fromleft to right while the player faces the symbol display 7. At the timeof stoppage of the symbols, the symbols are stopped at a time intervalof, e.g., 0.5 seconds. When a combination of predetermined symbols isdisplayed along any of the pay lines as a result of the symbols havingcome to a halt, a win associated with the combination of symbols isprovided.

[0051] A token payout port 15 and a token receiver 16 are provided at alower portion of the front panel 3. A game presentation indicator 17which is driven for providing game presentation is provided at an upperportion of the front panel 3. The game presentation indicator 17 isformed from, e.g., an LCD (liquid-crystal display) or lamps of varioustypes. The embodiment shows an example where an LCD is adopted. A bonusgame indicator 18 is provided at an upper portion of the front panel 3.The bonus game indicator 18 is formed from an LED (light-emittingdiode). The bonus game indicator 18 displays winning or acquisition of abonus prize which offers a high gaming value to the player, gamepresentations, and occurrence of an error. Speakers 19 produce soundguidance, music, sound effects, or the like. When a win has arisen for abonus prize, a game is developed in a manner advantageous to the player;for example, a game is developed such that the probability of occurrenceof a win becomes one-third.

[0052] A plurality of lamps 20 provided on the front panel 3 effectdisplay of a game, such as display of a validated pay line or display ofoccurrence of a win, in accordance with the number of inserted tokens(or the amount of a betted credit) through illumination, extinction, orblinking. The reserved token insert button 21 is for using only apredetermined number of tokens reserved in an unillustrated tokenstorage. A reserved token infusion button 22 is for using a maximumspecified number of tokens reserved in the unillustrated token storage.A reserved token count display 23 displays the number of tokens storedin the unillustrated token storage. A win count display 24 displays thenumber of times a win has arisen or the number of remaining games at thetime of occurrence of a win for a bonus prize. A payout token countdisplay 25 displays the number of tokens to be paid. The reserved tokencount display 23, the win count display 24, and the payout token countdisplay 25 are each formed from, e.g., an LED. A settlement button 26effects settlement of reserved tokens. A locking device 27 locks a doorwhen turned in a proper direction. The type and manufacturer of thegaming machine 1 are provided on a label 28.

[0053]FIG. 2 is a block diagram showing an electrical configuration ofthe gaming machine 1 of the embodiment. As shown in FIG. 2, the gamingmachine 1 is electrically made up of a main board A and a sub-board B.The main board A has a CPU 30, ROM 31, and RAM 32 and performs controloperation in accordance with a preset program. In addition to storing acontrol program to be used for controlling operation of the gamingmachine 1, the ROM 31 stores a prize group sampling table to be used fordetermining a prize group in advance (through internal lottery). The CPU30, the ROM 31, and the RAM 32 constitute a symbol selector.

[0054] The CPU 33 is connected to a clock generator 33 for generating areference clock pulse and to a random number generator 34 for generatinga given random number. The CPU 30 and the random number generator 34constitute a random number selector. By way of an output port 35, acontrol signal sent from the CPU 30 is output to a token payout device36, which pays tokens, and to a symbol display controller 37, whichcontrols the symbol display 7.

[0055] A signal output from a token discriminator 38 for determiningwhether or not a token is genuine; a signal output from a payout tokencounter 40 for counting the number of tokens to be paid; and a signaloutput from a start lever 41 which starts spinning of reels are input tothe CPU 30 by way of an input port 43. The signal output from the CPU 30is output to the sub-board B by way of a data transmitter 46 undercontrol of a transmission timing controller 45 for controlling a timingat which a signal is to be transmitted to the sub-board B.

[0056] In the sub-board B, the signal output from the data transmitter46 is input to a data receiver 47. The signal input to the data receiver47 is processed by a CPU 48. The CPU 48 is connected to a clockgenerator 49 for generating a reference clock pulse, ROM 50 havingvarious programs and image data recorded therein, and RAM 51. Datapertaining to images are output from the CPU 48 to a liquid-crystaldisplay 53 via a display processor 52, which performs image processingoperation. The liquid-crystal display 53 displays characters, a stillimage, a moving image, and the like.

[0057] Data pertaining to sound are output from the CPU 48 to anamplifier 56 via a sound LSI 54, which performs sound processingoperation. The sound LSI 54 extracts required sound data from sound ROM55, thereby processing sound data. Sound data which have been subjectedto processing, such as amplification, performed by the amplifier 56 areoutput to a speaker 58 via a sound controller 57.

[0058] Operation of the gaming machine of the embodiment having theforegoing configuration will now be described with reference to FIGS. 3through 8. In FIGS. 5 through 8, symbols other than a temporary symbol62, a trigger symbol 60 and substantial symbols 70, 80 are representedas blanks, and specific display of the symbols is omitted.

[0059] First, an ordinary game start operation is performed (step S1).Here, as mentioned above, one or more pay lines are specified by the BEToperation performed by the player, and the start lever 11 is actuated.Next, random numbers to be used for determining stop numbers of thefirst through fifth reel strips are acquired (step S2). A determinationis made as to whether or not a win has arisen for an ordinary game (stepS3). Then, spinning of the first through fifth reels is started (stepS4).

[0060] Spinning of the first through fifth reels is sequentially stopped(step S5). Here, the reels are sequentially stopped from the first reelto the fifth reel at predetermined time intervals. Time intervals can beset to a value of, e.g., 0.5 seconds. As shown in FIG. 4, adetermination is made as to whether or not a trigger symbol 60 showing asubmarine 61 is displayed on the first reel (step S6). Here, as shown inFIG. 5, the trigger symbol 60 is displayed on the first reel 71. Next, adetermination is made as to whether or not the symbol showing asubmarine pier is displayed in block of the fifth reel 75 (step S7).Here, as shown in FIG. 5, the temporary symbol 62 showing a submarinepier is displayed on in the block of the fifth reel 75. Since thetrigger symbol 60 and the temporary symbol 62 have been displayed on thesymbol display 7, a requirement for transforming the temporary symbol 62to a substantial symbol is satisfied.

[0061] Next, as shown in FIG. 6, the submarine drawn on the triggersymbol 60 appearing in the block of the first reel 71 starts movingtoward the temporary symbol 62 appearing in the block of the fifth reel75 (step S8). At this time, in order to enhance the effect ofpresentations, a pulse sound or the like which is produced when thesubmarine 61 travels across the ocean floor may be emitted. When thesubmarine 61 has arrived at the temporary symbol 62 showing thesubmarine pier, the temporary symbol 62 intensively illuminates,whereupon background scenery for the submarine pier of the temporarysymbol 62 appears. A determination is then made as to what is in thebackground scenery behind the temporary symbol 62 on the fifth reel 75of the submarine pier (step S9).

[0062] As shown in FIG. 7, when a substantial symbol 70 having atreasure chest drawn is displayed on the fifth reel 75, a treasure chestgame is activated (step S10). In contrast, as shown in FIG. 8, if asubstantial symbol showing ruins is displayed in the block on the fifthreel 75, a ruins game is activated (step S11). Here, both the treasurechest game and the ruins game are bonus games for offering profits tothe player. As a result, when the temporary symbol has appeared, theplayer can feel premonition of a bonus game.

[0063] As mentioned above, the temporary symbol and the substantialsymbol are associated with each other in a one-to-one correspondence. Ifthe requirement is not satisfied, the temporary symbol does nottransform to the substantial symbol. The requirement is that, in theembodiment, the temporary symbol 62 and the trigger symbol 60 must bedisplayed. When the temporary symbol 62 and the trigger symbol 60 havebeen displayed, the temporary symbol 62 transforms to a correspondingsubstantial symbol (70 or 80). At this time, the associated substantialsymbol becomes evident to the player. Thereby, when the temporary symbol62 is displayed, the player's expectation for display of the triggersymbol 60 can be enhanced. When the temporary symbol 62 and the triggersymbol 60 have been displayed, the temporary symbol 62 transforms to thesubstantial symbol (70 or 80), and the player's expectation forappearance of a substantial symbol can be enhanced.

[0064] In step S6, when the trigger symbol 60 showing a submarine is notdisplayed in the block of the first reel 71 and when the temporarysymbol 62 showing a submarine pier is not displayed in block of thefifth reel 75, processing proceeds to step S12.

[0065] Finally, game result processing is performed (step S12), andprocessing returns to a game start standby state.

[0066] In the description, the trigger symbol 60 appears in the firstreel 71 and the temporary symbol 62 appears in the fifth reel 75.However, the reel in which each of the trigger symbol 60 and thetemporary symbol 62 appears is not limited to the above unless theyappear in the same reel.

[0067] In the description, one type of symbol; that is, a symbol showinga submarine pier, is used for the temporary symbol 62. However, aplurality of types of temporary symbols having different appearances maybe used. In addition to the symbol showing a submarine pier, a symbolshowing a door may be employed. As a result, any of these temporarysymbols is displayed, the player encounters difficulty in predictingcorrespondence between the temporary symbol and a substantial symbol.Thus, when the temporary symbol is displayed, the player's expectationcan be enhanced.

[0068] Further, display of a plurality of temporary symbols may beemployed as the requirement. Specifically, the gaming machine isconfigured such that temporary symbols can transform to substantialsymbols when a plurality of temporary symbols, each showing a submarinepier, are simultaneously displayed. The gaming machine is alsoconfigured such that, when the temporary symbol showing a submarine pierand the symbol showing a door are simultaneously displayed, thetemporary symbols can transform to substantial symbols.

[0069] In this way, when the plurality of temporary symbols aredisplayed, each of the temporary symbols transforms to an associatedsubstantial symbol. At this time, the nature of the substantial symbolsassociated with the temporary symbols becomes evident to the player forthe first time, thereby enhancing the player's expectation aroused whenthe temporary symbol is displayed.

[0070] A plurality of trigger symbols may be provided, and display of aplurality of trigger symbols along with a temporary symbol may be set asthe requirement. For example, a symbol showing a door is taken as atemporary symbol; and a symbol showing a key and a symbol showing asubmarine are taken as trigger symbols. When the temporary symbolshowing a door, the trigger symbol showing a key, and the trigger symbolshowing a submarine are displayed simultaneously, presentation isoffered such that the door of the temporary symbol is opened and thetemporary symbol is transformed into the substantial symbol.

[0071] As mentioned above, when the temporary symbol and the pluralityof trigger symbols are displayed, the temporary symbol transforms to anassociated substantial symbol. At this time, the substantial symbolassociated with the trigger symbols becomes evident. As a result, whenthe temporary symbol has been displayed, the player's expectation foremergence of a plurality of trigger symbols can be enhanced. When thetemporary symbol is displayed in conjunction with a plurality of triggersymbols, the temporary symbol transforms to a substantial symbol.Therefore, the player's expectation for emergence of a substantialsymbol can be enhanced.

[0072] Moreover, lapse of a predetermined period of time since atemporary symbol was displayed may also be determined as therequirement. When a predetermined period of time has lapsed since atemporary symbol was displayed, the temporary symbol transforms to anassociated substantial symbol. At this time, the nature of thesubstantial symbol becomes obvious to the player for the first time. Asa result, when the temporary symbol has been displayed, the player'sexpectation for emergence of a substantial symbol can be enhanced.

[0073] Moreover, a plurality of clusters which differ in layout patternsuch that symbols are arranged around each temporary symbol may beadopted. As mentioned above, the cluster corresponds to a group formedfrom a plurality of symbols; that is, a group of symbols. A plurality oftypes of symbols are variably displayed in the direction of a column,whereas the variably-displayed symbols are stationarily displayed on thebasis of result of internal lottery operation. Since the pattern intowhich symbols are to be arranged around the temporary symbol differsfrom one cluster to another cluster, the player becomes able to predicta substantial symbol associated with the temporary symbol by the symbolslocated in the vicinity of the temporary symbol.

[0074] For instance, in the case of the reels which variably displaysymbols in the direction of a column (i.e., the vertical direction ofthe gaming machine), there is shown a case where three symbols aredisplayed; one in an upper row, one in a middle row, and the other in alower row. In this case, in each cluster, two symbols located in anupward direction with reference to the temporary symbol differ in layoutpattern from two symbols located in a downward direction with referenceto the same. Specifically, under the assumption that symbols arerepresented by capital letters and that a symbol showing a submarinepier to be taken as a temporary symbol is taken as symbol A, symbols ina certain cluster are arranged from an upper side to lower side of thereel; for example, “B, C, A, D, E.” In other clusters, symbols may bearranged such as “D, E, A, B, C” or “F, G, A, H, I.”

[0075] Therefore, we assume that symbols of a certain cluster arearranged into a pattern of “B, C, A, D, E” and that the substantialsymbol associated with the temporary symbol A is a symbol for starting abonus game. When the temporary symbol A is displayed in, e.g., an upperrow and when symbol “D” has come to the middle row and symbol “E” hascome to the lower row, the player can predict that the temporary symbolA is a substantial symbol for activating a bonus game. As a result, apredictive function (declaring occurrence of a win) can be realized,thereby arousing the player's interest.

[0076] The invention can be applied not only to the gaming machine usingthe foregoing reels, but also to a gaming machine by which the playerplays card games, such as poker or black jack, while images of cards arebeing displayed. For example, the invention can also be applied to agaming machine which offers a bingo game.

[0077] The previously-described characteristic operations of the gamingmachine of the invention are performed by causing a computer to executea control program.

[0078] The program is available while being recorded on a recordingmedium, such as a CD-ROM or a DVD. Further, such a program is alsoavailable by receiving a signal transmitted from a computer serving alsoas a transmitter, via a communication network constituted of atransmission medium, such as a public telephone line, a privatetelephone line, a cable television line, or a radio communication line.The signal is computer data embodied in the form of a predeterminedcarrier wave including a program. At the time of transmission, the onlyrequirement is to transmit at least a portion of the program over thetransmission medium. Namely, there is no necessity for all the dataconstituting the program to exist in the transmission medium at a singletime. A method for transmitting the program from the computer includes asituation in which data constituting the program are consecutivelytransmitted and a situation in which the data are transmittedintermittently.

[0079] Although the present invention has been shown and described withreference to specific preferred embodiments, various changes andmodifications will be apparent to those skilled in the art from theteachings herein. Such changes and modifications as are obvious aredeemed to come within the spirit, scope and contemplation of theinvention as defined in the appended claims.

What is claimed is:
 1. A gaming machine, comprising: a random numberselector, which selects at least one random number; a display, whichdisplays at least one of plural symbols in accordance with the selectedrandom number, the plural symbols including at least one first symbolwhich is associated with a second symbol in a one-to-one correspondence;and a replacement controller, which replaces the first symbol with thesecond symbol when a predetermined requirement is satisfied under acondition that the first symbol is displayed in the display.
 2. Thegaming machine as set forth in claim 1, wherein the display firstdisplays the plural symbols variably, and then displays at least one ofthe plural symbols stationarily in accordance with the selected randomnumber.
 3. The gaming machine as set forth in claim 1, wherein theplural symbols includes plural kinds of first symbols appearances ofwhich are different from each other.
 4. The gaming machine as set forthin claim 2, wherein the predetermined requirement is that a plurality offirst symbols are stationarily displayed in the display.
 5. The gamingmachine as set forth in claim 2, wherein the plural symbols includes atleast one third symbol, and the predetermined requirement is that thefirst symbol and the third symbol are stationarily displayed in thedisplay.
 6. The gaming machine as set forth in claim 5, wherein thepredetermined requirement is that the first symbol and a plurality ofthird symbols are stationarily displayed in the display.
 7. The gamingmachine as set forth in claim 2, wherein the predetermined requirementis that a predetermined time period elapses from when the first symbolis stationarily displayed in the display.
 8. The gaming machine as setforth in claim 2, further comprising a cluster in which the pluralsymbols are arranged according to a predetermined order with regard tothe first symbol, wherein the display comprises a plurality of displayareas, each operable to display the plural symbols arranged in thecluster.
 9. The gaming machine as set forth in claim 2, furthercomprising a plurality of clusters in which the plural symbols arearranged according to different orders with regard to the first symbol,wherein the display comprises a plurality of display areas, eachoperable to display the plural symbols arranged in one of the clusters.10. A method of controlling a gaming machine, comprising steps of:selecting at least one random number; displaying, in a display, at leastone of plural symbols in accordance with the selected random number, theplural symbols including at least one first symbol which is associatedwith a second symbol in a one-to-one correspondence; and replacing thefirst symbol with the second symbol when a predetermined requirement issatisfied under a condition that the first symbol is displayed in thedisplay.
 11. The method as set forth in claim 10, wherein the pluralsymbols are variably displayed first, and then at least one of theplural symbols is displayed stationarily in accordance with the selectedrandom number.
 12. The method as set forth in claim 11, wherein thepredetermined requirement is that a plurality of first symbols arestationarily displayed in the display.
 13. The method as set forth inclaim 11, wherein the plural symbols includes at least one third symbol,and the predetermined requirement is that the first symbol and the thirdsymbol are stationarily displayed in the display.
 14. The method as setforth in claim 13, wherein the predetermined requirement is that thefirst symbol and a plurality of third symbols are stationarily displayedin the display.
 15. The method as set forth in claim 11, wherein thepredetermined requirement is that a predetermined time period elapsesfrom when the first symbol is stationarily displayed in the display.